A study of HL-A antigen phenotype in rheumatic fever and rheumatic heart disease patients

Rheumatic fever and rheumatic heart disease: genetics and pathogenesis

Molecular mimicry between streptococcal and human proteins is considered as the triggering factor leading to autoimmunity in rheumatic fever (RF) and rheumatic heart disease (RHD). Here, we present a review of the genetic susceptibility markers involved in the development of RF/RHD and the major immunopathological events underlying the pathogenesis of RF and RHD. Several human leucocyte antigen (HLA) class II alleles are associated with the disease. Among these alleles, HLA-DR7 is predominantly observed in different ethnicities and is associated with the development of valvular lesions in RHD patients. Cardiac myosin is one of the major autoantigens involved in rheumatic heart lesions and several peptides from the LMM (light meromyosin) region were recognized by peripheral and intralesional T-cell clones from RF and RHD patients. The production of TNF-alpha and IFN-gamma from heart-infiltrating mononuclear cells suggests that Th-1 type cytokines are the mediators of RHD heart lesions while the presence of few interleukin-4 producing cells in the valve tissue contributes to the maintenance and progression of the valvular lesions.

Immunopathological mechanisms in bacterial-host interactions

The ability of bacteria to cause immunopathological damage in the host may take a variety of forms. These pathways may be conveniently grouped under three major headings: (1) organisms that can cause damage via shared antigenic determinants between host and bacterium; (2) those organisms that suppress the host’s response; and (3) organisms that release substances with specific biological properties or have receptors for specific tissue sites. The group A streptococcus is among the most versatile of these bacteria because it appears that it may use all three pathways in various streptococcal-related disease states. In rheumatic fever and chorea it appears that cross-reactive antigens play a major role in inducing immunopathological damage in that there is both a heightened humoral and cellular reaction by the host to these cross-reactive determinants. Recent evidence also indicates that rheumatic fever individuals express certain B cell antigens that may be associated with susceptibility to the disease. In the other complications of streptococcal infections, namely poststreptococcal glomerulonephritis, the bacterium uses both suppression of the host’s immune response and the excretion of a particular protein common to all nephritis-associated strains to achieve its immunopathological damage. In this context, other examples of bacterial-host interactions will be discussed as evidence for the common pathways used by microbes to cause immunopathological damage in the host.

Increased frequency of the C4A*6 rare allele in rheumatic heart disease

The aim of the present investigation was to determine whether the alleles of the MHC class III complement proteins BF, C2 and C4 (C4A and C4B) could be markers for RHD in the Brazilian population. Forty-nine patients with chronic RHD were studied. The controls included 65 healthy unrelated individuals, matched with the patients according to sex, age and ethnical background. BF, C2, C4A and C4B allotypes were determined by standard technologies including Western blots for C2 and C4 variants with monoclonal and policlonal antibodies. The results showed a significantly elevated presence of the C4A*6 rare allele (p = 0.003 RR = 11.85) and a decrease of C4A*3 in the patients. In addition, C4 null and BF and C4 rare alleles were more frequent in patients than in the controls. Considering that in this investigation only RHD patients were included, further studies are necessary in order to clarify whether C4A6 is a marker for the cardiac form or for the disease itself.

HLA antigens in Turkish race with rheumatic heart disease [see comment]

BACKGROUND

Rheumatic valvular disease has been reported to be associated with HLA antigens. To determine whether genetic factors could be involved in the pathogenesis of rheumatic heart disease (RHD), we analyzed the distribution of HLA-A, HLA-B, and HLA-DR antigens in Turkish patients with chronic rheumatic heart disease.

METHODS AND RESULTS

The association of class I and class II HLA antigens was examined in 107 ethnic Turkish patients with chronic RHD. The diagnosis was supported by echocardiography, cardiac catheterization, angioventriculography, and histological findings in patients who underwent valve replacement. Two hundred three control subjects, also of Turkish origin, were chosen. The phenotypes B16, DR3, and DR7 were encountered in a significantly higher frequency in patients with RHD compared with the control population (corrected p < 0.05, p < 0.00005, and p < 0.0005, respectively). There also was a decrease in the antigen frequency of DR5 in patients compared with controls (corrected p < 0.005).

CONCLUSIONS

The results are consistent with the hypothesis that susceptibility to RHD is genetically linked, and this in turn may be associated mainly with HLA class II antigens and weakly with class I antigens, with DR3, DR7, and B16 influencing susceptibility and DR5 conferring protection.

Beta haemolytic streptococci and musculoskeletal sepsis in adults

Lancefield group A streptococci (GAS) account for 3-17% cases of septic arthritis, but other beta haemolytic streptococci (BHS) (groups B, C, and G) are being increasingly implicated. Epidemiological evidence suggests that the increase of BHS sepsis in adults is a true increase and not simply a reflection of better reporting. While underlying predisposing disease and old age are common concomitants of BHS sepsis, some subjects with devastating disease have been young and healthy. This is particularly the case for highly virulent M1 serotypes of GAS, where a toxic shock-like syndrome has led to a number of deaths in young adults in the United Kingdom and elsewhere. Musculoskeletal features, such as myalgias, painful swollen limbs, myositis, and fasciitis, are important features of this condition, so that rheumatologists may be involved in management. Group C and G musculoskeletal sepsis remains uncommon, with a high prevalence of underlying predisposing disease, or pre-existing arthritis in the septic joint. Group B BHS septic disease appears to be increasing in incidence. Musculoskeletal sepsis with these organisms usually takes place in subjects with other diseases, but healthy subjects have not been spared. Multiple septic foci and a rapidly destructive arthritis are not uncommon, and a recently described extra-articular feature is potentially blinding metastatic endophthalmitis. Clinicians need to be aware of an apparently increasing incidence of BHS musculoskeletal sepsis in adults so that early identification can lead to aggressive management in these potentially fatal infections.

Beta haemolytic streptococci and reactive arthritis in adults

There is an increasing occurrence of reactive group A beta haemolytic streptococci (BHS) phenomena. This review makes a case for considering BHS in the differential diagnosis of adult reactive arthritis. This is based on (a) published reports over the past 45 years describing first attacks of rheumatic fever in adults; (b) the longstanding observation that polyarthritis is the most commonly expressed Jones major criterion in adults; (c) the broad spectrum of clinical expression of disease following streptococcal infection, with the re-emergence of the term 'poststreptococcal reactive arthritis'. The arthritis in adult rheumatic fever is characterised by sequential involvement of large weightbearing joints. Recurrent, severe, prolonged arthritis has been a prominent feature of adult poststreptococcal reactive arthritis. Carditis has been reported in 33% of adult patients with rheumatic fever. Consequently long term antibiotic prophylaxis for adults with reactive BHS phenomena should be strongly considered, and guidelines are suggested for this in individual patients. Further areas for research are discussed, particularly the interrelations between bacteria and host in disease expression, and the possibility that BHS might play a part in chronic arthritides and vasculitides.

Abnormal fibroblast clone--an alternative hypothesis for pathogenesis of rheumatic heart disease

Fibrosis is an ubiquitous process. Any tissue injury can culminate in fibroblast accumulation and multiplication with collagen synthesis and deposition. A large number of chronic disease states such as rheumatic heart disease, constrictive pericarditis, cirrhosis of the liver, renal interstitial fibrosis, chronic interstitial lung disease are characterized by extensive fibrosis. In many of these patients, when there is no clinical or laboratory evidence of previous injury, it is presumed that the initiating insult/injury had been 'subclinical'. I propose that 1) the fibroblasts can be activated even in the absence of preceding inflammation, 2) it is the type of 'fibroblast clone' in a given individual together with the 'milieu' in a particular tissue/organ which decides the occurrence and severity of subsequent fibrosis. This fibroblast clonal theory adds a new dimension to the pathogenesis of various disease states and may help in identifying those at high-risk and in evolving a unified therapeutic strategy for amelioration of various disorders characterized by extensive fibrosis.

Association of HLA class I and class II antigens with rheumatic fever in a Turkish population

The distribution of class I and class II HLA antigens of 100 Turkish patients with rheumatic fever, 77 of whom had cardiac involvement, was examined. We compared the results with a control group of identical origin. The frequency of HLA A10 and HLA B35 antigens were found significantly higher in patients with rheumatic fever (p < 0.05, p < 0.01, respectively). The frequency of HLA A10 and HLA DRw11 in patients with cardiac involvement were significantly higher than in those without cardiac involvement (p < 0.05, p < 0.01, respectively). On the other hand, HLA Cw2 antigen frequency was found significantly higher in patients without cardiac involvement than in those with rheumatic heart disease (p < 0.05). We support the concept that rheumatic fever is an immunological reaction to group A, beta hemolytic streptococci in individuals who have genetic predisposition.

HLA and rheumatic fever in Turkish Children

We report the results of research on human leukocyte allo-antigen (HLA) and rheumatic fever (RF), the first published study to be carried out among Turkish children with RF. Ninety-three Turkish children, aged between 6 and 16 years (mean: 8 +/- 2.6), with RF participated in the study. Of the total, 26 patients had their first attack and 39 had acute rheumatic activity at the time of registration. The results demonstrate (1) negative but not significant association between HLA-A2 and RF; (2) a positive association between HLA-DR4 and RF (p less than 0.001); (3) a significant association between HLA-DR4 and carditis, but not with isolated arthritis. These results corroborate the concept of race-specific genetically determined familial susceptibility to the development of rheumatic heart disease.

Frequency of D8/17 B lymphocyte alloantigen in north Indian patients with rheumatic heart disease

Ninety patients with rheumatic heart disease and 50 age- and sex-matched healthy human volunteers representing a North Indian population were typed for the B cell alloantigen D8/17 using a monoclonal antibody and a single step immunofluorescence technique. This alloantigen was expressed in 66.44% patients with RHD as compared with 14% of the normal population. A high relative risk (RR = 11.13) indicated a strong association of D8/17 B cell alloantigen with rheumatic heart disease. Increase in the frequency of the marker was observed with increasing age up to the fifth decade (40-49 years) in these patients. However, the frequency of this alloantigen, in the present study, in North Indian patients with rheumatic heart disease is lower than that reported in the American population.

Association of human leukocyte class II antigens with rheumatic fever or rheumatic heart disease in a Brazilian population

BACKGROUND

The incidence of rheumatic heart disease is great in Brazil. We analyzed the distribution of human leukocyte (HLA) antigens in a Brazilian population sample with rheumatic fever or rheumatic heart disease, with the aim of better understanding the mechanisms involved.

METHODS AND RESULTS

HLA class I (A, B, and C) and class II (DR and DQ) antigen distribution was studied in 40 patients with diagnosis of rheumatic fever or rheumatic heart disease and compared with a control group of 617 healthy individuals for class I typing, from which 118 were drawn for class II typing. A strong correlation between rheumatic fever and rheumatic heart disease and HLA-DRw53 (72.9% in the disease group versus 39% in the control group: p = 0.00061, relative risk, 4.2; etiologic fraction, 0.43) was found. We also found an increase in the frequency of HLA-DR7 (57.5% in the disease group versus 26.3% in control group: p = 0.00715; relative risk, 3.8; etiologic fraction, 0.56). HLA class I and HLA-DQ typing did not point to any association with these diseases.

CONCLUSIONS

HLA-DR7 and HLA-DRw53 are markers for susceptibility to rheumatic fever and rheumatic heart disease in Brazil. These results could be explained by genetic differences resulting from racial or geographical diversity.

Presence of a non-HLA B cell antigen in rheumatic fever patients and their families as defined by a monoclonal antibody

Numerous investigators have suspected that there is a genetic predisposition to rheumatic fever (RF). In this context we have recently produced a series of monoclonal antibodies directed against B cells obtained from RF patients one of which, labeled D8/17, identifies a B cell antigen present in 100% of all RF patients studied. While the highest percentage of positive cells were exhibited by RF probands (33.5% +/- SE), the percentage of cells in unaffected siblings and parents was 14.6 and 13%, respectively. The percentage of positive cells in APSGN probands, unaffected siblings, and parents was 2.96, 3.86, and 2.8%, respectively. A low level of B cells (5-7%) bearing the D8/17 marker was seen in control patients. The segregation pattern of the phenotypes defined by the percentage of D8/17 positive cells within HLA-typed RF families are consistent with an autosomal recessive mode of inheritance not associated with the human MHC system. We postulate that these phenotypes indicate the presence of at least one necessary genetic factor for susceptibility to RF.

Cell surface markers and cellular immune response associated with rheumatic heart disease: complex segregation analysis

A series of functional and cell surface markers associated with a significantly increased risk of rheumatic heart disease were analyzed for the contribution of genetic factors in their presence. Peripheral blood lymphocytes from nine large kindreds from the New Zealand Maori, Polynesian, and Caucasian populations were isolated, purified, and evaluated with lymphocyte surface markers (monoclonals 83S.19.23 and D8103), as well as studied for blastogenic response to a purified group A streptococcal extracellular product, blastogen A. Segregation analysis of blastogenic response and percent of cells positive for these cell surface markers was consistent with genetic control by single major genes; however, the contribution by polygenes varied by marker, indicating heterogeneity of genetic control of identification of cell surface glycoproteins and blastogenic response to streptococcal products.

A genetic marker for rheumatic heart disease

The frequency of antigen types (A, B, C, and DR) in an unselected group of 25 patients with chronic rheumatic heart disease and an unselected group of 15 patients with acute rheumatic fever was compared with that in a group of 100 healthy volunteers. All patients and controls were Arabs of Saudi origin. Only the frequency of HLA-DR4 was significantly different in the controls and the patient groups--controls 12%, chronic rheumatic heart disease 72%, acute rheumatic fever 53%, both patient groups together 65% (relative risk 13.6 with 95% confidence interval 10.5-16.7). Eighty three per cent of 12 patients with mitral stenosis and 70% of seven with aortic incompetence had HLA-DR4 antigen. In 17 non-Saudi Arab patients who had acute rheumatic fever or chronic rheumatic heart disease, the frequency of HLA-DR4 was identical (65%) to that in Saudi patients. These findings may have implications for the pathogenesis of rheumatic fever and rheumatic heart disease.

HLA-A, B, DR, and DQ antigens in black patients with severe chronic rheumatic heart disease

To determine whether genetic factors could be involved in the pathogenesis of rheumatic heart disease, we performed HLA-A and HLA-B typing in 120 black patients with severe chronic rheumatic heart disease requiring cardiac surgery, and HLA-DR and HLA-DQ typing in 103 and 97 of these patients, respectively. The HLA typing was done by a standard microlymphocytotoxicity method. Patients were 12 to 60 years old (mean 27.6 +/- 14.5). No differences in HLA-A, HLA-B, and HLA-DQ frequencies between patients and controls were noted. HLA-DR 1 antigen was present in 12.6% of patients compared with 2.7% of normal control subjects (corrected p less than .045; relative risk = 5.2) and the HLA-DRw6 antigen was present in 31.1% of patients compared with 15% of control subjects (corrected p less than .045; relative risk = 2.6). These findings suggest that genetically determined immune-response factors may play a role in the pathogenesis of severe chronic rheumatic heart disease.

HLA-DR typing and lymphocyte subset evaluation in rheumatic heart disease: a search for immune response factors

Several autoimmune diseases have been associated with increased frequencies of specific histocompatibility (HLA) antigens, particularly for the D (DR) locus, that may be linked to immune response genes. Rheumatic valvular heart disease (RHD) has been postulated to have autoimmune features, but HLA associations have not been established. We, therefore, performed HLA-DR typing in 33 consecutive patients with RHD and in 82 normal blood bank control subjects. We also evaluated the frequencies of lymphocyte subsets by means of monoclonal antibodies and immunofluorescence flow cytometry and made functional correlations for the natural killer cell (NKC) in patient subsets. The DR patterns in RHD were heterogeneous. However, significant differences were noted for DR4 and DR6. DR4 was present in 52% (17 of 33) of RHD patients vs 32% (26 of 82) of control subjects (p less than 0.05). DR6 was present in 6% (2 of 33) of patients vs 26% (21 of 82) of control subjects (p less than 0.02). The associated relative odds of DR4 was 2.3 and the etiologic fraction was 0.30. The relative odds of DR6 was 0.19 and the preventive fraction was 0.21. A distinct clinical profile was not associated with DR4 positivity or DR6 negativity. The frequency of lymphocyte subsets was not significantly changed except for OKT8. Median NKC numbers tended to be higher in RHD patients than in control subjects (p less than 0.05). In contrast, NKC functional activity tended to be lower in RHD; median lymphocyte to target cell (K562 line) ratio resulting in 50% killing (L/T 50) was 20.5 in RHD patients vs 11.5 in control subjects (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

HLA antigens in 88 cases of rheumatic fever observed in Martinique

HLA-A, B, C and DR antigens were studied in 88 patients from Martinique. A modest but significant reduction of B14 and Bw42 antigens was noted as well as an increase in B35 (p less than 0.05) and DR1 antigens (corrected p less than 0.05), two antigens known to be in linkage disequilibrium. These data, which corroborate a previous study for B35, suggest that the unusual antistreptococcal response mounted by rheumatic fever patients is under HLA control.

Association of class II human histocompatibility leukocyte antigens with rheumatic fever

The association of class I and II HLA antigens with rheumatic fever and its manifestations was examined in 72 patients, including 48 blacks and 24 Caucasians. No significant association was found between class I antigens and rheumatic fever. In contrast, HLA-DR2 and HLA-DR4 phenotypes were encountered in a significantly higher frequency in black and Caucasian patients with rheumatic fever, respectively, compared with the control populations (P less than 0.005). The most significant association (P less than 0.005) of these DR antigens with a major manifestation of rheumatic fever was found for mitral insufficiency. In addition, a significant association was encountered between persistent elevation of antibody to the group A streptococcal carbohydrate and HLA-DR4 in Caucasian patients (P less than 0.04) or HLA-DR2 in the black patients (P less than 0.001). The frequency of HLA-DR2/4 heterozygotes among patients with rheumatic fever did not differ significantly from controls. These findings support the concept of a genetically determined susceptibility to rheumatic fever and, particularly, to rheumatic heart disease. The association of the clinical manifestations of rheumatic fever and the immune hyperresponsiveness to a streptococcal antigen could be ascribed to a disease-associated immune-response gene which is in linkage disequilibrium with the DR2 and DR4 alleles of HLA-DR locus on chromosome six.

Rheumatic fever-associated B cell alloantigens as identified by monoclonal antibodies

Mice immunized with B lymphocytes obtained from patients who had had well-documented rheumatic fever in the past yielded 2 monoclonal antibodies, termed 83S19.23 and 256S10, which identified certain alloantigens present on the B cells of these patients. The frequency of the B cell marker detected by clone 83S19.23 in rheumatic fever patients was found to be 59%, 77%, and 74% in India, New Mexico, and New York, respectively. Monoclonal antibody 256S10 identified 75% of those rheumatic fever patients who were nonreactive to clone 83S19.23. Thus, the 2 antibodies identify approximately 92% of all rheumatic fever patients and suggest the presence of a diallelic genetic marker for susceptibility to rheumatic fever.

HLA antigens and acute rheumatic fever: evidence for a recessive susceptibility gene linked to HLA

From 60 probands with acute rheumatic fever (ARF), 19 multiplex families segregating for ARF were ascertained. The parents and rheumatic and normal sibs of the probands in these 19 families were also studied. HLA typing using the microlymphocytotoxic assay was then performed on the 60 unrelated probands, the multiplex families, and 234 unrelated controls using 23 antigens from the HLA-A and -B loci. The controls lacked a past history of ARF and were from the same geographic locality. Calculations of relative risk demonstrate an increase of HLA-B5 antigen in the 60 patients, but the result might not be significant from the point of view of multiple comparisons. Nevertheless, affected sib pairs from the multiplex families show 93% concordance for both or one HLA haplotype. A formal linkage analysis demonstrates that a recessive etiology is most likely (lod score of 3.3) with approximately 68% of cases being due to a gene closely linked to HLA and in linkage disequilibrium with HLA-B5. The remaining 32% of cases are due to other familial factors such as polygenic inheritance or common environmental factors. The results confirm a strong genetic predisposition to ARF and its heterogeneous nature in families.

Plaque and systemic disease: a reappraisal of the focal infection concept

The review presented here covers metastatic local and systemic disease secondary to the accumulation of plaque or the formation of other pathogenic microbial depots in the mouth. At least 3 pathways may link oral infection to secondary disease, to wit metastatic infection due to transient bacteremia, metastatic immunological injury, and metastatic toxic injury. The available evidence is presented and examples are provided. They concern among others such divergent diseases as acute bacterial myocarditis, infective endocarditis, brain abscess, uveitis and iridocyclitis, trigeminal and atypical facial neuralgia, unilateral facial paralysis, fever of "unknown' origin, and neutrophil dysfunction.

Sharing of HLA haplotype by parents of patients with systemic lupus erythematosus

Forty-four families were studied for the relationships between HLA and systemic lupus erythematosus (SLE). Nine families had more than 1 member with SLE; haplotype sharing between SLE patients within a family was no greater than expected by chance. Fourteen of 236 relatives had antinuclear antibodies (ANA); the frequency of haplotype sharing between SLE patients and ANA-positive relatives was no greater than expected by chance. One HLA-A,B haplotype was shared by 7 of 35 parent pairs, a frequency (20%) significantly greater (P = 0.004) than in 2 groups of normal controls (3.1% and 5%). These data provide evidence for HLA-linked genes operating recessively in the expression of SLE.

Rheumatic heart disease and thyroid status

A retrospective analysis of 76 patients with rheumatic heart disease revealed nine with thyrotoxicosis, three with hypothyroidism and seven with normal thyroid function and circulating thyroid antibodies. This suggests that there may be an association between rheumatic heart disease and thyroid dysfunction. The findings emphasize the need to formally exclude hyperthyroidism in patients with atrial fibrillation whatever the apparent cause. They also imply a possible autoimmune factor in the pathogenesis of rheumatic heart disease and suggest that patients with rheumatic heart disease may develop clinical or sub-clinical thyroid disease.

HLA antigens in black South African children with rheumatic heart disease

The high incidence of rheumatic heart disease (RHD) in black South African children has been attributed mainly to poor socio-economic status and over-crowding. In order to elucidate whether other factors, in particular genetic, were responsible, the HLA-status of 61 black children with rheumatic heart disease was compared with that of 1165 normal controls. Overall, no differences were found, except a higher incidence of HLA-B25 and BW51 in the group with rheumatic heart disease, when the difference was not of statistical significance. Moreover, when the patients were considered in two groups, viz. (a) a "surgical" group which required cardiac surgery and (b) a "non-surgical" group in which cardiac failure was absent or could be easily controlled by medical therapy, the difference between the two groups was also not of statistical significance, though there was a higher incidence of HLA-A10 (which includes HLA-A25 and A26) in the "non-surgical" group. These data appear to agree with the results of other studies which found no significant association between HLA-status and RHD.

Role of macrophage-dependent determinant selection in induction phase of streptococcal carditis

A genetically controlled antigen-presentation function in macrophages is proposed to explain the induction phase of streptococcal carditis. Antigenic determinants in strains of beta-haemolytic streptococci causing rheumatic fever are selected by macrophages, through the operation of immune response (Ir) genes, to be presented to T lymphocytes. Cross-reactivity between the selected determinants and heart tissue components generates clones of autoreactive T cells. Autoimmunity will develop if, coincidental with the presentation of the relevant antigenic determinant, regulation of T-cell production is disturbed. This hypothesis explains the capacity of different strains of streptococcus to produce rheumatic fever and also the variability in host susceptibility to the disease.

Detection of immune complexes in acute rheumatic fever and their relationship to HLA-B5

Employing five radioimmunoassays for immune complexes, the sera of 45 acute and 27 postacute follow-up sera from patients with acute rheumatic fever were examined. All patients experienced actue polyarthritis. Complexes were detected in 89% of acute-phase sera by one assay, 51% by two, 29% by three, and 7% by four. Immune complex values decreased significantly at followup, although some abnormalities persisted. There was no correlation between extra-articular manifestations and the occurrence of circulating immune complexes. Those positive for HLA-B5 demonstrated a significantly more pronounced immune response as measured by circulating immune complexes. The data indicate that circulating immune complexes occur frequently in adults with acute rheumatic fever. The relative frequency of immune complexes detected by multiple techniques in B5-positive, compared with B5-negative, patients suggests a genetic basis for the development of immune complexes in these patiemts.

The HLA antigens and ABO blood groups in an American Black population with mitral valve prolapse

A total of 42 American Black patients with mitral valve prolapse and 194 healthy individuals of similar ethnic background were tested for the distribution of various HLA antigens and ABO blood groups. The most significant result was an increased frequency of Bw35 in patients (74%) as compared with controls (39%), with a P value of less than 0.0001; the relative risk was 4.45.

A study of HLA antigens in adults with acute rheumatic fever

By use of a microlymphocytotoxic assay to detect 32 HLA antigens of the A and B series, we examined 49 Mexican-American adults with acute rheumatic fever and contrasted the findings with 100 ethnically identical controls. Eighty-nine percent of the total possible antigens were identified. Strong associations between HLA antigens from either locus and acute rheumatic fever were not detected. These findings serve to emphasize the importance of nongenetic factors in the pathogenesis of acute rheumatic fever and help clarify the role of HLA antigens in rheumatic diseases.

HLA antigens and acquired valvular heart disease

The frequency of HLA antigens was determined in 133 patients with acquired valvular heart disease and compared with the frequency of HLA antigens in 1,000 normal individuals by the relative incidence ratio method of Woolf (1955). No significant increases were observed. However, when the patients were divided into those with no rheumatic history and those who have had rheumatic fever or chorea, a significant increase in AW 30/31 and A29 was observed in the group with no rheumatic history.

A study of HL-A types in Rh haemolytic disease of the newborn

The HL-A types of 288 women, immunised to the Rh(D) antigen as a result of pregnancy, have been compared to the HL-A types of 139 women who although they have had Rh(D)-positive children have not produced anti-Rh(D). There is an indication that an increased incidence of the HL-A3 antigen is associated with the immunised mothers. A study of the HL-A types of husbands and children of both immunised and non-immunised women did not suggest that their HL-A types played a significant role in anti-Rh(D) production. The frequencies of the HL-A antigens in each category studied have been tabulated for record purposes, as well as the frequencies in a random panel of persons living in the Newcastle environs. Full ABO, Rh and HL-A details of 50 immunised mothers and their families and of 58 non-immunised mothers and their families are available.